Display device and method for fabricating the same

Abstract

A display device includes a planarization layer including a first planarization unit on a substrate and a second planarization unit on the first planarization unit, a pixel electrode on the second planarization unit, an organic pattern layer on the pixel electrode, a light emitting element on the organic pattern layer and having a downwardly convex recess on a top surface thereof, a first partition wall on one surface of the first planarization unit and forming a space around the light emitting element, a via layer in the space around the light emitting element, a first reflective layer around a side of the first partition wall in the space around the light emitting element, on the first planarization unit, and around a side of the light emitting element, a side of the organic pattern layer, and a side of the pixel electrode.

What is claimed is: 
     
         1 . A display device comprising:
 a planarization layer comprising a first planarization unit on a substrate and a second planarization unit on the first planarization unit;   a pixel electrode on the second planarization unit;   an organic pattern layer on the pixel electrode;
 a light emitting element on the organic pattern layer and having a downwardly convex recess on a top surface thereof; 
   a first partition wall on one surface of the first planarization unit and forming a space around the light emitting element;   a via layer in the space around the light emitting element;
 a first reflective layer around a side of the first partition wall in the space around the light emitting element, on the first planarization unit, and around a side of the light emitting element, a side of the organic pattern layer, and a side of the pixel electrode; 
 an insulating organic layer covering a portion of the top surface of the light emitting element, an upper portion of the via layer, and a portion of an upper portion of the first partition wall; and 
 a common electrode extending along bottom and side surfaces of the recess on the top surface of the light emitting element, a top surface of the insulating organic layer, and a top surface of the first partition wall, 
   wherein the second planarization unit has an undercut shape in which a side surface of the second planarization unit is located towards a center of the pixel electrode from a side surface of the pixel electrode, and the first reflective layer has a discontinuous structure due to the undercut shape.   
     
     
         2 . The display device of  claim 1 , wherein the light emitting element comprises a first semiconductor layer, an active layer, a second semiconductor layer, and a third semiconductor layer sequentially stacked, and wherein the recess is formed from a top surface of the third semiconductor layer to the second semiconductor layer toward the second semiconductor layer to expose a portion of the second semiconductor layer, and the common electrode is in direct contact with the exposed portion of the second semiconductor layer. 
     
     
         3 . The display device of  claim 2 , wherein the light emitting element further comprises an element reflective layer on a bottom surface of the first semiconductor layer; an insulating layer around sides of the element reflective layer, the first semiconductor layer, the active layer, the second semiconductor layer, and the third semiconductor layer; and a pad connection electrode on a bottom surface of the element reflective layer and in direct contact with the element reflective layer and the first reflective layer. 
     
     
         4 . The display device of  claim 3 , wherein the insulating layer is further located on the bottom surface of the element reflective layer and has an opening exposing at least a portion of the element reflective layer,
 wherein the pad connection electrode contacts the element reflective layer through the opening.   
     
     
         5 . The display device of  claim 4 , wherein the pad connection electrode electrically connects the first semiconductor layer and the pixel electrode through the element reflective layer and the first reflective layer. 
     
     
         6 . The display device of  claim 2 , wherein one end of the insulating organic layer meets one end of the recess on the light emitting element. 
     
     
         7 . The display device of  claim 6 , wherein the recess has a regular tapered shape. 
     
     
         8 . The display device of  claim 2 , wherein side surfaces of the light emitting element and side surfaces of the organic pattern layer are aligned with each other. 
     
     
         9 . The display device of  claim 8 , wherein the pixel electrode protrudes further outward than a side of the organic pattern layer. 
     
     
         10 . The display device of  claim 1 , wherein the first partition wall has a same height as the light emitting element and has an inverted tapered shape. 
     
     
         11 . The display device of  claim 10 , further comprising a second partition wall located on the first partition wall, wherein the second partition wall has a height that is equal to or shorter than that of the first partition wall and has an inverted tapered shape. 
     
     
         12 . The display device of  claim 1 , wherein the recess has a width of 40% or more of a width of the light emitting element. 
     
     
         13 . The display device of  claim 1 , further comprising: a capping layer on the common electrode and covering the common electrode;
 a second partition wall disposed on the capping layer to overlap the first partition wall;   a second reflective layer around a side of the second partition wall; and   a wavelength conversion layer disposed in a space formed by the second partition wall.   
     
     
         14 . The display device of  claim 13 , further comprising an overcoat layer and a color filter layer sequentially disposed on the wavelength conversion layer and the second partition wall. 
     
     
         15 . A method of manufacturing display device comprising:
 forming an undercut shape on a substrate on which a first planarization unit, a second planarization unit, and a pixel electrode are stacked in an order by etching the second planarization unit to expose the first planarization unit, and wherein a side of the second planarization unit is located towards a center of the pixel electrode from a side of the pixel electrode;   bonding a light emitting element by forming an organic pattern layer on the pixel electrode;   forming a first partition wall on the first planarization unit to surround the light emitting element;   depositing a reflective material layer to cover both the first partition wall and the light emitting element;   forming a via layer in a space formed by the first partition wall, and forming a reflective layer by etching a reflective material layer on an upper portion of the light emitting element not covered by the via layer;   forming an insulating organic layer having an opening on a top of the light emitting element;   forming a downwardly recessed recess on a top surface of the light emitting element by etching the light emitting element with the insulating organic layer as a mask; and   forming a common electrode in direct contact with the recess of the light emitting element.   
     
     
         16 . The method of  claim 15 , wherein bonding the light emitting element by forming the organic pattern layer on the pixel electrode comprises:
 fully applying an organic pattern material layer on the substrate to cover the first planarization unit and the pixel electrode;   arranging the light emitting element to be aligned with the pixel electrode on the organic pattern material layer; and   bonding the light emitting element by curing the organic pattern material layer.   
     
     
         17 . The method of  claim 16 , wherein bonding the light emitting element by forming the organic pattern layer on the pixel electrode further comprises:
 ashing the organic pattern material layer that is not overlapped with the light emitting element to form the organic pattern layer.   
     
     
         18 . The method of  claim 15 , wherein the first partition wall comprises a negative photosensitive material and has an inverted tapered shape which has a width that decreases in a downward direction. 
     
     
         19 . The method of  claim 15 , further comprising:
 forming a capping layer on the common electrode to cover the common electrode;   forming a second partition wall on the capping layer to overlap the first partition wall;   forming a second reflective layer around a side surface of the second partition wall; and   forming a wavelength conversion layer in a space formed by the second partition wall.   
     
     
         20 . The method of  claim 19 , further comprising:
 forming an overcoat layer and a color filter layer sequentially located on the wavelength conversion layer and the second partition wall.